Closely related to this question; I want both Flurry of Blows and Decisive Strike on the same character. Decisive Strike as the main combat strategy for the build, and Flurry of Blows because it's a requirement for all the feats I can find that would let me Decisive Strike with the weapon I want to use (mind blade, though short sword or longsword would also work).

Are there any classes/feats/etc. other than Monk that grant the class feature "Flurry of Blows"? (It has to be called exactly that, or otherwise count as FoB for prerequisites.)

Or are there any classes/feats/etc. other than Monk that grant an ability like Decisive Strike? This one doesn't have to be as exact; I just want a shtick like this as my main combat strategy. I would prefer to do so with Decisive Strike from Monk, because this is supposed to be for a Monk competition, and just having FoB for the sake of saying I do while using an unrelated shtick in combat would be lame.

For the sake of completeness, the feats I know of that could make the mind blade a monk-special-weapon are Flowing Blade (web), Unorthodox Flurry (Dragon Compendium), and Whirling Steel Strike (Eberron Campaign Setting). Note how all three have "flurry of blows class feature" as a prerequisite.

\$\begingroup\$I like this question - there are all sorts of things that (seemingly) you can literally only qualify for with a Monk level, and it's a requirement I've found onerous in the past.\$\endgroup\$
– MinimanMar 25 at 7:07

So disciple of the eye straight up has a class feature called “Flurry of Blows (Ex),” and it explicitly discusses how that works for non-monks. That’s the gold standard right there.

Arcanopath monk and monk of the enabled hand both use the word “gains” in reference to flurry of blows, as part of larger class features that explain getting and/or progressing various monk class features. These both seem explicit and clear to me.

Less explicit and clear, sun soul monk and Tashalatora both say that monk levels and certain non-monk levels stack to determine flurry of blows. Nothing says that monk levels can’t be 0 in either case, which is fairly-widely accepted as allowing non-monks to gain flurry of blows, but the rules are less explicit and it doesn’t sit well with some DMs.

As evidence for sun soul monk and Tashalatora, though, I would point to the serene guardian from Shattered Gates of Slaughtergarde. The serene guardian explicitly gives non-monks bonus feats instead of progressing monk features, so it isn’t an answer here, but for monks, when it does progress those features, it explicitly progresses “flurry of blows attack bonus,” not flurry of blows as a whole. This is evidence for things like sun soul monk and Tashalatora, which do progress flurry of blows wholesale, allowing non-monks to access flurry of blows.

Now then, in the case of a monk who has taken decisive strike, we may have a problem.All of these are say you get flurry of blows “as a monk” would, or that your levels “stack with monk levels” for flurry of blows. Except your monk class doesn’t give you flurry of blows if you have taken decisive strike. It may not really matter—after all, most of them refer to “a monk” or “monk levels” rather than “your monk levels” or that “you get as a monk” or something. So maybe they refer to some generic monk, one that presumably didn’t take decisive strike. This is a totally reasonable interpretation of the text—but the whole situation is on very iffy footing because there just isn’t any explicit handling of the possibility.

Even if we acknowledge this as a fatal flaw in the whole plan, the disciple of the eye still gives you a class feature called “flurry of blows,” so for prerequisites rather than using the thing, it’s sufficient even if we rule it does nothing for you.

But really, if there is a problem, it’s purely authorial error and oversight. Alternate class features as a concept didn’t show up in all that many books, they weren’t something that authors wrote around. The rules for ACFs themselves don’t really address the problem, either, though they should. Originally, they were a variant idea in Unearthed Arcana, which was full of variant ideas that really needed a bit more DM adjudication and adaptation than your typical sourcebook. But Player’s Handbook II didn’t do that when it used the concept, which I think is a failing. Even though Player’s Handbook II as a sourcebook “should be” just usable “as is,” I think in this regard it isn’t, and a DM should work with players on these kinds of issues. Decisive strike should just count as flurry of blows for prerequisites in the first place, really. But if it doesn’t, then your monk levels shouldn’t inhibit you from getting flurry of blows from things that would ordinarily give it to non-monks (or stack with the existing one that monks are assumed to have). But nothing of this situation is clarified by the rules, so you will have to ask your DM about that.

Anyway, for the record, Tashalatora is by a large margin the best option of these. Of the more explicit cases, disciple of the eye is by far the easiest to enter—it just requires Improved Unarmed Strike, Concentration and Spot at 8 ranks, and the dragonblood subtype (which is available from many races or by taking the Dragontouched feat). Both arcanopath monk and monk of the enabled hand require three weak feats (Dodge, Mobility, Deflect Arrows or Combat Expertise, Improved Disarm, Deflect Arrows) in addition to Improved Unarmed Strike and some other minor requirements. Disciple of the eye also definitely has the strongest class features of the three, plus it has that benefit of being something that works for prereqs absolutely no matter what.

\$\begingroup\$I think you're right about iffy RAW as far as progressing FoB when you've got Decisive Strike from monk instead... but for my purposes, that doesn't actually matter too much. Disciple of the Eye has FoB as a class feature, so regardless of whether it does anything, it qualifies you for any of the feats that let you make a weapon a monk special weapon, letting you use them with Decisive Strike.\$\endgroup\$
– Poetically PsychoticMar 25 at 18:13

\$\begingroup\$@PoeticallyPsychotic Good point, I’ll add that to the answer.\$\endgroup\$
– KRyanMar 25 at 18:44

For getting both class features, I already have one possible solution, but it's... rather cheesy.

The Symbiotic Creature template (Savage Species) gives you all the special attacks and special qualities of the host and guest. A quick look through the Monster Manuals suggests that all class features are either special attacks or special qualities. If either the host or the guest has Flurry of Blows, the other could have Decisive Strike E.g. a Kobold Monk 1 as the guest and a Half-Ogre Monk 1 (with Human Heritage to meet the type requirement) as the host.

Using this in the final build would be a last resort. (Although it would make an interesting way of representing General Grievous, with his humanoid mind controlling a robotic body...)

For features like Decisive Strike, the Overwhelming Attack Fighter ACF is basically identical. Shame it's not available until Fighter 16. More than a little bit restrictive as far as build options.